/*
 *                               POK header
 *
 * The following file is a part of the POK project. Any modification should
 * be made according to the POK licence. You CANNOT use this file or a part
 * of a file for your own project.
 *
 * For more information on the POK licence, please see our LICENCE FILE
 *
 * Please follow the coding guidelines described in doc/CODING_GUIDELINES
 *
 *                                      Copyright (c) 2007-2021 POK team
 */

/* s_ilogbf.c -- float version of s_ilogb.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#ifdef POK_NEEDS_LIBMATH

#include "math_private.h"
#include <libm.h>

int ilogbf(float x) {
  int32_t hx, ix;

  GET_FLOAT_WORD(hx, x);
  hx &= 0x7fffffff;
  if (hx < 0x00800000) {
    if (hx == 0)
      return 0x80000001; /* ilogb(0) = 0x80000001 */
    else                 /* subnormal x */
      for (ix = -126, hx <<= 8; hx > 0; hx <<= 1)
        ix -= 1;
    return ix;
  } else if (hx < 0x7f800000)
    return (hx >> 23) - 127;
  else
    return 0x7fffffff;
}

#endif
